The present disclosure relates to containers, particularly to containers having one or two metal ends applied to one or both ends of the container body and crimp-seamed or double-seamed onto the container body, and most particularly to such containers used for retort processing and in which the container body is non-metallic.
Traditionally, retort containers have been constructed substantially entirely of metal. For many decades the standard retort food container has been the metal can, in which a metal can body is closed by a pair of metal ends that are double-seamed onto the ends of the can body. Each metal end has an outer peripheral portion forming a “curl” that receives the end of the can body, and after each end is applied the curl and the end of the can body are rolled up together to form a double seam. This construction has the great advantage that it readily withstands retort processing without the seams being compromised, because the plastically deformed metal of the can body in the seam area tends to hold its deformed shape despite the stress and high temperature during retort.
More recently there has been a desire to construct retort containers that use less metal, motivated by the potential cost reduction and improved aesthetics that such a construction can offer. The development described in the present disclosure addresses this desire.